Glass of very rapid fusion and high point of transformation



Patented May 3, 1949 UNITED STATES PATENT OFFICEK GLASS OF VERY RAPIDFUSION AND HIGH POINT OF TRANSFORMATION Andr Danzin and Edouard Despois,Paris,

France, assignors to Societe Francaise Radio- Electrique, a corporationof France No Drawing. Application May 13, 1947, Serial No. 747,836. InFrance December 27, 1945 Section 1, Public Law 690, August 8, 1946Patent expires December 27, 1965 2 Claims. (Cl. 106-53) 1 2 Thisinvention relates to the manufacture of Percent glass and has for itsobject to provide glasses ZnO 3, of very rapid fusion and high point oftranS- AS203 0.4 What we claim is:

More specifically the invention, seeks to pro- 1 A glass of lowexpansion, low temperature vlde Improved glasses t adaptied for workmgof fusion, relatively high temperature of softenmto pressed t m f 9 bying and high fluidity at temperatures a little chines fed with glass inthe llquid state. The above that of Softening having a compositionproperties mainly required in such a glass are: (1) a low co-efficientof expansion; (2) a very Wlthm the followmg tablelow temperature offusion; (3) a relatively high Percent temperature of softening(Littleton point in the S102 34 to 33 neighbourhood of 680), and (4)good fluidity at PbO 24 to 30 temperature only a little above thesoftening B203 20 to 26 temperature. A1203 3.5 to 5.5 According to thisinvention a glass having the ZnO 8 to 9 above properties is made with acomposition fall- 2 A glass as claimed 1n claim 1 having an exmg wltmnthe followmg table pansion suited to that of molybdenum having thePercent following composition: S10: 34 to 38 Percent PbO A 24 to 30SiO'z 36 B203 20 to 26 PbO A1203 3.5 to 5.5 B203 25 ZnO 8 to 9 A1203 5Other matter 0 to 1 25 ZnO 8.6 With such glasses good fluidity can be010- A520 tained at relatively low temperature this permitting themanufacture of non-deformable ANDRE DANZIN- glass parts at about 500 to550. EDOUARD DESPOIS- A preferred glass having the following compositionpossesses a co-efiicient of expansion REFERENCES CITED which accordswell with that of molybdenum: The following references are of record inthe Percent file of this patent: $102 1 36 UNITED STATES PATENTS NumberName Date 2,431,983 Bastick et al Dec. 2, 1947

